Report estimated run time in the GUI before a simulation

[nwagenbrenner]

An IMET recently asked about the option of having WindNinja report the estimated run time to the user once all of the inputs have been set. Not sure if there is a reliable way we could do this since it depends on hardware, etc., but maybe we could come up with a way to generate at least ballpark estimates based on number of cells in the mesh and number of timesteps.